The present invention relates to a steering column fastening arrangement for a motor vehicle with an energy-absorbing deformation element which is arranged between a steering bracket retained on the side of the body and a tubular protective steering member.
A steering column fastening arrangement is disclosed already in the DE-OS No. 28 14 145 which includes an arrangement for the energy absorption in case of collisions by way of a deformation element. This deformation element is connected with the steering column and includes zigzag-shaped deformation sections. A plastic deformation of the element takes place in case of an impact by way of a retaining member on the side of the body which cooperates with the deformation element by means of a bolt. However, this prior art arrangement consists of a large number of individual components which are costly to install and which does not assure a safe mounting of the steering column at the vehicle body by way of these elements.
It is the object of the present invention to provide a steering column fastening arrangement including a deformation element which with a simple construction consists of few individual parts to be non-costly in manufacture and which assures a safe and reliable fastening of the steering column at the vehicle body.
The underlying problems are solved according to the present invention in that the deformation element consists of a plate rigidly connected with a U-shaped member of the tubular protective steering member, which includes slot-like deformation sections that are arranged corresponding to elongated apertures of the U-shaped member, in which are guided displacement bolts extending through the deformation sections that retain the tubular protective steering member at the steering bracket fixed at the body.
In the steering column fastening arrangemet according to the present invention, the same only needs to be constructed as deformation member whereby the plate-shaped construction thereof offers the advantage of a small structural space. Therebeyond, the deformation member is formed of few parts which are assembled on the outside and can then be installed in the vehicle in a simple manner.
Owing to the deformation element with slot-like deformation sections which consists in a suitable manner of a relatively thin metallic plate, this element can absorb a sufficient deformation path without significant stress concentration and the element will effect a step-wise progressive energy absorption as a result of a collision.
By the additional arrangement of a cup spring between the head of the displacement bolt and the U-shaped member, the axial fixing force of the bolt is defined and the deformation path is correspondingly influenced.